Locus of inhibition in the masked priming of response alternatives

Masked prime stimuli presented immediately before target stimuli in a choice reaction task give rise to behavioral costs when the primes and the target stimuli are mapped to the same response and result in benefits when they are mapped to opposite responses. Researchers assume that this negative compatibility effect reflects inhibitory processes in the control of perceptuomotor links. The authors investigated whether the inhibition operates at the level of abstract central codes or at effector-specific motor stages. In 2 experiments (N = 8 participants in each), left or right hand or foot responses were required to target stimuli that were preceded by masked arrow primes mapped to the same response side as the target stimuli in compatible trials and to the opposite response side in incompatible trials; the primes were irrelevant in neutral trials. In Experiment 1, when the masked primes determined both response side and modality, there was no transfer of negative compatibility effects across response modalities. That finding is inconsistent with a central abstract locus of inhibition and suggests that inhibition operates at effector-specific motor stages. In Experiment 2, primes conveyed only response side information but left response modality uncertain, and negative compatibility effects were elicited for both hand and foot responses, suggesting that partially informative masked primes can trigger a parallel activation and subsequent inhibition of response processes within separate effector systems.     

Experiences of longing in Norwegian and Swedish 4- and 5-year-old children

Longing can be defined as a blend of the primary emotions of happiness and sadness. These primary emotions are experienced very early by children, and the meanings of the words happiness and sadness are also known by children early in their verbal development. To find out at what age children are able to understand and use the more developed concept of longing, the authors interviewed 74 preschoolers (4- and 5-year-olds) in Norway and Sweden about their experiences of longing. Chi-square analyses showed age and sex differences in knowledge of the concept, and some differences between categories of longing were also significant. Results showed that young children's ability to understand and use the concept of longing appears to be limited and that girls seem to mature earlier in this respect than boys do.     

Relation of maximal ankle dorsiflexion angle and passive resistive torque to passive-elastic stiffness of ankle dorsiflexion stretch

The maximal passive ankle dorsiflexion angle and the maximal passive resistive torque at this angle were measured for 81 women 20 to 84 years of age and correlated with the passive-elastic stiffness (stiffness) of an ankle dorsiflexion stretch. Pearson correlation coefficients and multiple regression analyses were used to examine whether the two clinical measurements could predict ankle stiffness. The maximal passive resistive torque showed a moderate correlation with stiffness in the full stretch range (r = .69) and high correlation with stiffness in the last half of the full stretch range (r = .84). The maximal dorsiflexion angle showed a low correlation with stiffness in the full stretch range (r = .27) and in the last half of the full stretch range (r = .36). The maximal passive resistive torque and the dorsiflexion angle together accounted for 54% of the stiffness variance in the full stretch range and 76% of the stiffness variance in the last half of the full stretch range. Thus, the clinical measurements of the maximal passive dorsiflexion angle and the maximal passive resistive torque were directly and significantly related to the ankle dorsiflexion passive-elastic stiffness and good predictors of stiffness in the last half of the passive ankle dorsiflexion stretch.     

Personality,mental distress,and risk perception in subjects with multiple chemical sensitivity and toxic encephalopathy

Personality, mental distress, and risk perception were assessed in (a) cases of multiple chemical sensitivity (MCS; n = 17), (b) chemically intolerant toxic encephalopathy cases (TE), type 2A (n = 31) and 2B (n = 26), and (c) healthy referents (n = 200). MCS cases showed elevated mental distress scores on the Depression, Interpersonal Sensitivity, Global Severity Index, and Somatization scales in the Symptom Checklist 90 (SCL-90). In the Karolinska Scales of Personality (KSP) the MCS group showed an elevation only on the Psychasthenia scale. Both TE groups showed elevations across the KSP anxiety scales Muscular Tension, Psychasthenia, and Somatic Anxiety. TE type 2B subjects also showed elevations on the Irritability and Indirect Aggression scales. However, neither MCS nor TE groups showed deviating personality characteristics in the Meta Contrast Technique test. Similarly, none of the groups deviated from referents in a risk perception inventory.     

Baseball outfielders maintain a linear optical trajectory when tracking uncatchable fly balls

The authors investigated whether behavior of fielders pursuing uncatchable fly balls supported either (a) maintenance of a linear optical trajectory (LOT) with monotonic increases in optical ball height or (b) maintenance of optical acceleration cancellation (OAC) with simultaneous lateral alignment with the ball. Past work supports usage of both LOT and OAC strategies in the pursuit of catchable balls headed to the side. When balls are uncatchable, fielders must choose either optical linearity or alignment at the expense of the other. Fielders maintained the LOT strategy more often and for a longer period of time than they did the OAC alignment strategy. Findings support the LOT strategy as primary when pursuing balls headed to the side, whether catchable or not.     

Simplified learning in complex situations: knowledge partitioning in function learning

The authors explored the phenomenon that knowledge is not always integrated and consistent but may be partitioned into independent parcels that may contain mutually contradictory information. In 4 experiments, using a function learning paradigm, a binary context variable was paired with the continuous stimulus variable of a to-be-learned function. In the first 2 experiments, when context predicted the slope of a quadratic function, generalization was context specific. Because context did not predict function values, it is suggested that people use context to gate separate learning of simpler partial functions. The 3rd experiment showed that partitioning also occurs with a decreasing linear function, whereas the 4th study showed that partitioning is absent for a linearly increasing function. The results support the notion that people simplify complex learning tasks by acquiring independent parcels of knowledge.     

Lower region: a new cue for figure-ground assignment

Figure-ground assignment is an important visual process; humans recognize, attend to, and act on figures, not backgrounds. There are many visual cues for figure-ground assignment. A new cue to figure-ground assignment, called lower region, is presented: Regions in the lower portion of a stimulus array appear more figurelike than regions in the upper portion of the display. This phenomenon was explored, and it was demonstrated that the lower-region preference is not influenced by contrast, eye movements, or voluntary spatial attention. It was found that the lower region is defined relative to the stimulus display, linking the lower-region preference to pictorial depth perception cues. The results are discussed in terms of the environmental regularities that this new figure-ground cue may reflect.     

Aphasia type and aging in Hindi-speaking stroke patients

In this study, the clinical profile of Hindi-speaking stroke patients with aphasia from northern India has been investigated. We examined the interactional effect between age and gender with aphasia type in 97 Hindi-speaking right-handed individuals, the majority of them with a confirmed diagnosis of a cerebrovascular accident. The subjects included in the study ranged from 3 weeks to two years post-onset with a diagnosis of a common classical aphasia (Broca's, Wernicke's, anomic, global, conduction, and transcortical) types involving both males and females. Also examined was the interaction between literacy and aphasia type since the subjects had varied exposures to education (total illiteracy to professional/university education). While the data reported here about Hindi-speaking aphasics are relatively in agreement with the age-aphasia type patterns discussed in western countries, nonetheless some differences were also observed. The mean age of Indian patients with aphasia was significantly lower. Also, in addition to some gender and literacy related differences, an outstanding difference was that many clinical symptoms that are known to co-occur with aphasia were not readily reported by subjects with stroke.